Immunomodulatory Activity of the Glycoprotein Isolated from the Chinese Yam (Dioscorea opposita Thunb)

The yam (Dioscorea opposita Thunb) is a well-known edible food and widely used as the traditional Chinese medicine. The present investigation was designed to evaluate the immunomodulatory activity of glycoprotein (DOT) from yam and explore its possible molecular mechanisms. Results showed that the DOT could improve the cell immunity, humoral immunity and phagocytic system function of the normal mice. The DOT could also increase the production of TNF-α, interleukin-6 and nitric oxide and enhance the pinocytosis function of macrophages. Furthermore, the DOT increased phosphor-p38, JNK, ERK1/2 and nuclear factor kappa B (NF-κB) p65 protein expression in peritoneal macrophages. Taken together, our data suggest that DOT could be used as a potential immunostimulant and exert its immunomodulatory activity via mitogen-activated protein kinases and NF-κB signal pathways.